The present invention relates to the use of chlorine-free fluorocarbons (FC), especially hydrogen-containing fluorocarbons (HFC), as constituents of release agent compositions; to a process for preparing such release agent compositions, and to the use of these compositions as release agents.
In many industrial processes, it is necessary to use agents with which the affinity between various materials, for example between a workpiece and a tool or between a molding and a mold, can be kept as low as possible. This is generally achieved by using release agents, depending on the working operation. Release agents are thus required for the production and processing of plastics, foams, building materials, rubber articles, tires, metals, glasses, ceramic products and the like which involve production techniques such as casting, shaping, pressing and the like. As used herein the term "release agent" refers to an agent which forms a solid or liquid film that reduces the adhesion between two adjacent surfaces, i.e. which prevents them from sticking together, and thus acts as a release agent, stripping agent or lubricant. Release agents may be solutions or dispersions of agents having a releasing action.
According to K. Schardt, Kunststoffe, Volume 72, pages 461-462, 1982, agents known to exhibit a releasing action include silicones, metal soaps, waxes, fatty oils, synthetic polymers and inorganic substances. Suitable solvents which may be mentioned include liquid aliphatic hydrocarbons, halogenated hydrocarbons and water.
The preparation of special wax derivatives which can be contained as ingredients having a lubricating and/or releasing action in release agents together with solvents is described in Canadian Patent No. CA 1,248,131. See also Feist et al., U.S. Pat. Nos. 4,659,493 and 4,746,463, the disclosures of which are hereby incorporated herein by reference. Solvents mentioned as suitable include the chlorofluorocarbons trichloromonofluoromethane (R11), 1,1,2-trichloro-1,2,2-trifluoroethane (R113), 1,1,2,2tetrachlorodifluoroethane (R112), tetrachloromonofluoroethane (R121) and/or trichlorodifluoroethane (R122).
Despite the efforts of the prior art, there remains a need for improved release agent compositions.